The first thing you’ll probably notice about OmniGraffle 3 is the paneled design. Navigation and object inspection are handled by the new panels. On an iPad or in landscape mode on a Plus-size iPhone, the panels slide in from the sides of the screen. On smaller iPhones or portrait mode on a Plus-sized iPhone, the panels slide up from the bottom of the screen.

[…]

The advantage of the panels is that, unlike popovers, they can remain onscreen as long as you need them, reducing the number of taps necessary to edit your document. The downside is that they take up space and when both panels are open things start to get a little crowded, even on a 12.9-inch iPad.

[…]

A console and fully-documented API reference describing the dozens of classes available for manipulating OmniGraffle documents [via JavaScript] is built right into the Pro version of the app.

Sounds like it’s about as Pro as it could possibly be on iPad. I’ll be interested to hear how well this works in practice on a small screen, and how well it sells at $49/$99 in the App Store.